Conventionally, backlight devices provided with a white light source such as a pseudo white LED (pseudo white light emitting diode) and an RGB-LED have been known.
A pseudo white LED is formed with, for example, a blue light emitting element and a fluorescent material that converts light emitted from the blue light emitting element into light having a longer wavelength than blue light. Here, pseudo white light is obtained through additive mixture of blue light and light having a longer wavelength than blue light. With a backlight device using such a pseudo white LED, pseudo white light includes a large amount of light whose wavelength is between B (blue) and G (green) (for example, a wavelength of 490 nm-510 nm) and a large amount of light whose wavelength is between G (green) and R (red) (for example, a wavelength of 570 nm-590 nm). As a result, when the pseudo white light obtained with such a backlight device is irradiated onto a display panel, a large amount of light whose wavelength is between B (blue) and G (green) is transmitted through the B and G regions of a color filter of the display panel, and a large amount of light whose wavelength is between G (green) and R (red) is transmitted through the G and R regions of the color filter of the display panel. This degrades color hues and color purity on the display panel. In addition, since wavelengths of B (blue) and G (green) are closer to each other than wavelengths of G (green) and R (red) are to each other, the color hues and the color purity of B (blue) and those of G (green) are particularly degraded.
On the other hand, an RGB LED is formed with blue, green and red light emitting elements. Here, white light is obtained through additive mixture of blue, green and red light. With such an RGB LED as well, since the wavelengths of B (blue) light and G (green) light are comparatively close to each other, light whose wavelength is between B (blue) and G (green) is transmitted through the B and G regions of the color filter of the display panel. This degrades color hues and color purity of B (blue) and those of G (green).
To cope with this, there have conventionally been proposed display devices provided with a backlight device capable of improving color hues and color purity on a display panel (see, for example, Patent Document 1).
Patent Document 1 discloses a liquid crystal display device provided with a white light source, a light guide plate on which light emitted from the white light source is incident, a color liquid crystal device (a display panel) which is irradiated with light emitted from the light guide plate, and a color correction plate (a filter member) which is placed on a light incident surface and/or a light emission surface of the light guide plate. Patent Document 1 teaches that the color correction plate absorbs light having a wavelength of around 500 nm and light having a wavelength of around 590 nm at a predetermined ratio. This helps prevent light that has passed through the color liquid crystal device from including a large amount of light whose wavelength is between B (blue) and G (green) or a large amount of light whose wavelength is between G (green) and R (red).    Patent Document 1: JP-A-2005-183139